A pressure regulator of air tank used in diving typically includes a rubber diaphragm, a lever, a spring, an air supply valve, a one-way valve leaf, etc., and has an outer case generally made of a rigid plastic material. When a diver inhales, air inside the pressure regulator decreases to cause reduction of internal pressure of the regulator, and the rubber diaphragm on the pressure regulator is forced by external pressure to bend inward and therefore presses against the lever, causing the lever to pull the spring and open the air supply valve. When the air supply valve is opened, air in the air tank is sent to the diver.
On the other hand, when the diver exhales, air pressure inside the regulator increases to push the rubber diaphragm outward, and the lever is moved to a normal position to release the spring and close the air supply valve. The exhaled air is discharged from the regulator via the one-way valve leaf.
The above-mentioned one-way valve leaf is mounted in a valve-leaf seat formed on the outer case of the pressure regulator. A protective cover is fitted onto the valve-leaf seat to protect the one-way valve leaf. The one-way valve leaf is a thin rubble sheet and plays an important role in the pressure regulator of the air tank for diving. To ensure the valve leaf to function in a normal manner, and to avoid the valve leaf from damage due to external force acted thereon, aging, or insufficient repair or maintenance, it is necessary to periodically maintain, clean, or replace the valve leaf. To do so, it is necessary to open the valve-leaf protective cover to expose the valve leaf. And, the valve-leaf protective cover must be closed again when the maintenance or replacement is completed.
FIGS. 1 and 2 are perspective views of a first conventional pressure regulator 1 of air tank used in diving with a valve-leaf protective cover 15 disassembled from and assembled to the pressure regulator 1, respectively. The pressure regulator 1 has an outer case, on which a valve-leaf seat 11 is formed for a one-way valve leaf 4 to mount therein. The valve-leaf seat 11 is provided at two lateral sides with two raised supports 12. Two shaft holes 13 are separately provided on the two raised supports 12 to locate at the same axial direction. A space 14 is defined between the two raised supports 12. A valve-leaf protective cover 15 having a configuration corresponding to that of the space 14 is positioned over the space 14. The valve-leaf protective cover 15 is provided with a shaft hole 16 to align with the two shaft holes 13 on the raised supports 12, so that a shaft 17 may be extended through the shaft holes 13 and 16 to connect the protective cover 15 to the valve-leaf seat 11 between the two raised supports 12 to protect the one-way valve leaf 4.
The shaft 17 must have a length and diameter closely matching with a distance between the two shaft holes 13 and a diameter of the shaft holes 13, 16. When the shaft 17 is too thick or too long, it is uneasy to mount it into the shaft holes 13, 16. And, when the shaft 17 is too thin or too short, it tends to move in and fall out of the shaft holes 13, 16. To maintain, clean, or replace the valve leaf 4, an elongate tool is required to remove the shaft 17 from the shaft holes 13, 16 before the protective cover 15 can be disassembled from the valve-leaf seat 11. It is very troublesome and time-consuming to do so. Moreover, the dismounted shaft 17 and protective cover 15 are fully separated from the pressure regulator 1 and therefore must be handled with special care to avoid missing thereof.
FIGS. 3 and 4 are perspective views of a second conventional pressure regulator 2 of air tank used in diving with a valve-leaf protective cover 25 disassembled from and assembled to the pressure regulator 2, respectively. The pressure regulator 2 has an outer case, on which a valve-leaf seat 21 is formed for a one-way valve leaf 4 to mount therein. The valve-leaf seat 21 is provided at an upper edge near two lateral sides with two projections 22, and at a lower edge near lateral sides with two symmetrically outward turned lips 23. The valve-leaf seat 21 has an open top 24 to which the valve-leaf protective cover 25 is closed. The protective cover 25 is provided at an upper rear surface with two retaining holes 26 corresponding to the two projections 22 on the valve-leaf seat 21. To assemble the protective cover 25 to the valve-leaf seat 21, first engage with the projections 22 with the retaining holes 26, and then apply a force to a lower part of the protective cover 25 to close it onto the valve-leaf seat 21, such that the outward turned lips 23 on two lateral sides of the seat 21 are pressed against two bubble outlets 27 provided at two lateral sides of the protective cover 25. In this manner, the valve-leaf protective cover 25 may be firmly connected to the valve-leaf seat 21 to protect the one-way valve leaf 4.
To maintain, clean, or replace the valve leaf 4, a driver or other suitable tool is required to pry the lips 23 of the valve-leaf seat 21 off the bubble outlets 27 of the protective cover 25, disengage the projections 22 from the retaining holes 26, and then remove the protective cover 25 from the seat 21. It is still troublesome and time-consuming to disassemble the protective cover 25 from the valve-leaf seat 21. And, the dismounted protective cover 25 is completely separated from the pressure regulator 2 and subjected to undesired missing thereof.